While the Raspberry Pi has very good support for an I2C bus, a lot of very cool chips – including the in system programmer for just about every ATtiny and ATmega microcontroller – use an SPI bus.

The £25 Raspberry Pi now has fully open-source drivers for its ARM System on a Chip (SoC) — paving the way for new operating systems like the Risc OS and Bell Labs Plan 9 to be brought to the board.

Broadcom and Raspberry Pi recently released the source code and documentation for a chip similar to the one used in the group’s mini-computer. But open source code is only as good as the applications ...